Conventional silicon breast implant augmentation mammaplasty (referring to FIG. 1) usually is performed by slitting an incision 100 at the armpit 10, or an incision 110 below the breast 11, or an incision 120 below the areola 12, then inserting a breast implant through the incision 100, 110 or 120 below the breast 11 to augment the breast. During such an operation some problems and difficulties occur, notably:
1. The silicon breast implant is quite bulky and difficult to be inserted manually through the incision 100, 110 or 120. The tissues around the incision 100, 110 and 120 easily become rotten and incision enlarged. Scar is hence easily formed and noticeable after operation.
2. The silicon breast implant is inserted forcefully by fingers through the incision 100, 110 or 120, and is possibly damaged. After a period of time the silicon breast implant could be leaking or disrupted to make the breast hardened or deformed, and result in operation failure.
3. By pushing forcefully the silicon breast implant through the incision 100, 110 or 120 with fingers surgeon's fingers could be hurt.
4. To implant the silicon breast implant through the incision 100, 110 or 120 by pushing with fingers, operation time is longer and results in unfavorable condition to patients.
To remedy the aforesaid problems, many techniques have been developed to make augmentation mammaplasty easier and more efficient. FIG. 2 illustrates a breast implant injector disclosed in U.S. Pat. No. 4,955,906. The breast implant injector 20 includes a hollow tube 21 and a bag 22. The tube 21 has a conical opening 212 at one end 211 which holds the bag 22 inside and beyond. The bag 22 has one end coupled with a slide element 221 which is slidable on the surface of the tube 21. There is a locking ring 23 located on an outer side of the tube 21 at the contact location of a nozzle 201 of the injector 20 and the bag 22. It aims to push a breast implant 24 into the body of a patient. But in practice it still has some drawbacks, notably:
1. The conical opening 212 can only be in inserted in a very shallow location at the incision site rather than in a proper depth. Unless the incision is made larger for the conical opening insertion deeper, the breast implant 24 cannot be inserted deeply inside from the incision and into the submammary pocket, thus the implanted breast implant 24 will easily loosens off after insertion. So that it does not provide much benefits to the operation.
2. The conical opening 212 and the one end 211 of the tube 21 are joined at a location where an unsmooth angular corner 2111 is formed. The angular corner 2111 creates a greater friction to the breast implant 24 and makes pushing out of the breast implant 24 through conical opening 212 difficult.
3. During pushing of the breast implant 24 the outer side of the bag 22 has to be pulled downwards toward the nozzle 201 by the injector 20 (referring to the arrow shown in FIG. 2). A great friction and resistance takes place while the bag 22 is located at the conical opening 212. Adding the resistance caused by the angular corner 2111, the bag 22 could be broken, and pushing out of the breast implant 24 is even more difficult.
Due to the aforesaid injector 20 encounters such a greater resistance during pushing and the breast implant 24 easily slips out during surgery, a disposable implant injector was developed (referring to U.S. Pat. No. 5,201,779 shown in FIGS. 3 and 4A) that has an injection opening expandable automatically. It includes an injection barrel 30. However it also has its own practical problems as follow:
1. It has a guiding rod 31 which is inserted into the injection barrel 30 through a tail end and has a front end extended outside an injection opening 32 where twelve pieces of flaps 33 are being extended first. As the twelve flaps 33 are formed by an injection process, they tend to stick together. Hence they have to be extended first by the front of the guiding rod 31 before they are inserted in the incision of a patient to allow the opening 32 to be disposed inside the incision. Then a plunger 35 with a hard head 351 is pushed forwards through a rear end of the injection barrel 30 as shown in FIG. 4A to inject a breast implant 34 through the opening 32 into a inner side of the breast of the patient for positioning. While the breast implant 34 is pushed and passes through the opening 32, the twelve flaps 33 are pushed by the breast prosthesis 34 to extend outward and form gaps among them. The breast implant 34 thus tends to be wedged in these gaps and damaged during it's being pushed to pass through the opening 32 (referring to FIG. 4B).
2. The injection barrel 30 gradually forms a tapered portion at the bottom of the opening 32 adjacent to the twelve flaps 33. Unsmooth angular corners 301 and 302 are formed at the junction that become obstacles during pushing of the breast implant 34 by the hard head 351 of the plunger 35 in the injection barrel 30. The breast implant 34 cannot be moved smoothly and clogging could occur. When the breast implant 34 reaches the angular corner 301 at the top end of the barrel and the bottom end of the angular corner 302, a greater resistance force is formed. As a result moving of the breast implant 34 is difficult.
3. Because of the inadequate design of twelve flaps 33, an extra element of the guiding rod 31 has to be provided. More unnecessary surgical procedure is needed because of this situation.